Field
This invention relates to optical sensor modules, and packaging therefor.
Description of the Related Art
Optical sensor modules are used in a variety of optical sensing applications. For example, gesture sensors may be used to detect movement of an object, such as a user's hand. Such detection can be processed, for example, allowing a user to provide input to an electronic device by making certain gestures. Gesture sensors can be used in a wide variety of fields such as consumer electronics, healthcare, or telecommunications. In addition, optical sensor modules may be used in various types of medical devices, such as heart rate monitors, oxygen sensors, etc. Components for such optical sensor modules can include an optical emitter, an optical sensor die, and an associated application-specific integrated circuit (ASIC). The ASIC may be configured to process the output signal from the optical sensor die.
With increasing emphasis on miniaturization, it is desirable to arrange an optical emitter, optical sensor, and ASIC closely together. In such arrangements, however, there may be risk of light pollution or cross-talk, in which some light from the optical emitter, either direct or reflected from some other component of the package, is detected by the adjacent optical sensor before being reflected by an object. Such cross-talk can decrease the performance of the assembly. Accordingly, there is a need for arrangements to minimize space occupied by an optical emitter, optical sensor, and ASIC, while reducing the risk of cross-talk between the emitter and the sensor.